ience Kant Makes it Dependent on Mind.]

Sect. 187. But what has become of the dream of the mathematical
physicist? Is the whole system of Newton, that brilliant triumph of the
mechanical method, unfounded and dogmatic? It is the logical instability
of this body of knowledge, made manifest in the well-founded scepticism
of Hume, that rouses Kant to a re-examination of the whole foundation of
natural science. The general outline of his analysis has been developed
above. It is of importance here to understand its relations to the
problem of Descartes. Contrary to the view of the English philosophers,
natural science is, says Kant, the work of the mind. The certainty of
the causal relation is due to the human inability to think otherwise.
Hume is mistaken in supposing that mere sensation gives us any knowledge
of nature. The very least experience of objects involves the employment
of principles which are furnished by the mind. Without the employment of
such principles, or in bare sensation, there is no intelligible meaning
whatsoever. But once admit the employment of such principles and
formulate them systematically, and the whole Newtonian order of nature
is seen to follow from them. Furthermore, since these principles or
categories are the conditions of human experience, are the very
instruments of knowledge, they are valid wherever there is any
experience or knowledge. There is but one way to make anything at all
out of nature, and that is to conceive it as an order of necessary
events in space and time. Newtonian science is part of such a general
conception, and is therefore necessary if knowledge is to be possible at
all, even the least. Thus Kant turns upon Hume, and shuts him up to the
choice between the utter abnegation of all knowledge, including the
knowledge of his own scepticism, and the acceptance of the whole body of
exact science.

But with nature thus conditioned by the necessities of thought, what has
become of its externality? That, Kant admits, has indeed vanished. Kant
does not attempt, as did Descartes, to hold that the nature which mind
constructs and controls, exists also outside of mind. The nature that is
known is on that very account phenomenal, anthropocentric--created by
its cognitive conditions. Descartes was right in maintaining that
sense-perception certifies to the existence of a world outside the mind,
but mistaken in calling it nature and identifying it with the realm of
science. In short